model qdr 4500 qdr for windows - frank's hospital ......hologic hologic inc. 35 crosby drive...

HOLOGIC

Hologic Inc.35 Crosby DriveBedford, MA 01730 USA

Phone in US: 800-321-4659Fax (Domestic): 781-280-0670

Fax (International): 781-280-0671

Document No.080-0811 Rev A

MODEL QDR®4500 QDR FOR WINDOWS®

FAN BEAM X-RAY BONE DENSITOMETER

TECHNICAL MANUAL

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NOTICEThe information contained in this Manual is confidential and proprietary to Hologic, Inc. Thisinformation is provided only to authorized representatives of Hologic's customers solely for thepurpose of facilitating the use of Hologic's products. No information contained herein may bedisclosed to any unauthorized person for any purpose whatsoever without the prior writtenconsent of Hologic, Inc.

Hologic QDR 4500 and the Hologic logo are registered trade marks of Hologic, Inc. All otherproducts and company names, used in this manual, are trademarks and registered trademarks ofother manufacturers.

Windows® and Windows® 98 are either registered trademarks or trademarks of MicrosoftCorporation in the United States and/or other countries.

The procedures described in this document are intended solely for use by direct employees ofHologic, Inc. or authorized Hologic Equipment Resellers and their trained field engineers. Anyunauthorized or untrained persons performing these procedures may affect the warranty of theHologic Model QDR 4500.

Exercise proper caution when servicing the system. There are dangerous and potentially lethalvoltages accessible within the QDR 4500 system. To avoid exposure to shock hazards, the Maincircuit breaker should be switched off, and the power cord removed, before working inside anypart of the system.

The QDR 4500 Fan Beam X-ray Bone Densitometer produces ionizing radiation in the form ofX-rays. It may be dangerous to the patient, operator or field engineer unless safe exposure factorsand operating instructions are observed. To avoid unsafe exposure, do not attempt to service thisequipment unless you are a Hologic, Inc. certified field engineers. Exercise proper caution whenservicing the system. A dosimeter (film badge) should always be worn while on site. Dose andscatter radiation measurements must be taken after each service call to ensure that theseparameters are still within specifications.

Hologic, Inc. has made all reasonable effort to ensure that the information in this manual isaccurate and complete. Hologic, Inc. shall not, however, be liable for any technical or editorialerrors or omissions contained herein, or for incidental, special or consequential damages inconnection with the furnishing or use of this material. The information contained in this manualis subject to change without notice.

Printed in U.S.A.

Copyright 1999, 2000 by Hologic, Inc., All rights reserved

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TABLE OF CONTENTSSECTION 1 INTRODUCTION .....................................................................................................1-1

SYSTEM OVERVIEW .............................................................................................................................................1-1X-RAY SCANNING THEORY ................................................................................................................................1-2FUNCTIONAL OVERVIEW....................................................................................................................................1-4PRODUCT SPECIFICATIONS ................................................................................................................................1-8

BMD Precision:...................................................................................................................................................1-10Duty Cycle:..........................................................................................................................................................1-10Leakage Technique Factors .................................................................................................................................1-10Minimum Beam Filtration ...................................................................................................................................1-10Measured Half Value Layer (HVL) At Different Operating Potentials ...............................................................1-11Line Voltage and Maximum Line Current...........................................................................................................1-11Technique Factors for Maximum Line Current ...................................................................................................1-11Maximum Deviation............................................................................................................................................1-11Measurement Criteria for Technique Factors ......................................................................................................1-11

SECTION 2 FUNCTIONAL DESCRIPTION................................................................................2-1COMPUTER..............................................................................................................................................................2-1COMMUNICATIONS CONTROLLER BOARD.....................................................................................................2-1

Interface Connections ............................................................................................................................................2-1DISTRIBUTION BOARD.........................................................................................................................................2-3

Power.....................................................................................................................................................................2-3Interface Connections ............................................................................................................................................2-4

MOTOR CONTROLLER BOARD ...........................................................................................................................2-5Power.....................................................................................................................................................................2-5Interface Connections ............................................................................................................................................2-6

TZ DRIVE BOARD...................................................................................................................................................2-7Service Switches....................................................................................................................................................2-7Power.....................................................................................................................................................................2-8Interface Connections ............................................................................................................................................2-8

CONTROL PANEL CONTROLLER BOARD .......................................................................................................2-11Power...................................................................................................................................................................2-11Interface Connections ..........................................................................................................................................2-12

C-ARM INTERFACE BOARD...............................................................................................................................2-15Continuity Daisy Chain .......................................................................................................................................2-15Power...................................................................................................................................................................2-15Interface Connections ..........................................................................................................................................2-16

X-RAY CONTROLLER ASSEMBLY....................................................................................................................2-18Interface...............................................................................................................................................................2-18X-Ray Controller Assembly Boards ....................................................................................................................2-20

I/O and Logic Board .......................................................................................................................................2-20Low Voltage Power Supply ............................................................................................................................2-20Power Factor Regulator (PFR) Substitution Board.........................................................................................2-21Duty Cycle Regulator......................................................................................................................................2-21H-Bridge Board...............................................................................................................................................2-21Interface Connections......................................................................................................................................2-21

X-RAY SOURCE UNIT..........................................................................................................................................2-26DATA ACQUISITION SYSTEM ...........................................................................................................................2-26

Solid State Detector.............................................................................................................................................2-27Power ..............................................................................................................................................................2-27Interface Connections......................................................................................................................................2-27

INTEGRATOR/MULTIPLEXOR BOARD ............................................................................................................2-28Power ..............................................................................................................................................................2-29Interface Connections......................................................................................................................................2-29

Analog To Digital Board .....................................................................................................................................2-30Power ..............................................................................................................................................................2-31

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Interface Connections .....................................................................................................................................2-31POWER MODULE .................................................................................................................................................2-32

SECTION 3 INSTALLATION.......................................................................................................3-1REQUIRED TOOLS .................................................................................................................................................3-1REQUIRED DOCUMENTATION............................................................................................................................3-1ROOM AND DOORWAY SIZE...............................................................................................................................3-2ARRANGE FOR HELP ............................................................................................................................................3-4INSPECT FOR VISIBLE SHIPPING DAMAGE .....................................................................................................3-4UNCRATE UNIT ......................................................................................................................................................3-5INSPECT FOR HIDDEN SHIPPING DAMAGE .....................................................................................................3-6TAKE INVENTORY.................................................................................................................................................3-6MEASURE PATH TO FINAL DESTINATION.......................................................................................................3-6

Short Doorway ......................................................................................................................................................3-6Narrow Hallway ....................................................................................................................................................3-7

REMOVE TABLE TOP (IF NECESSARY) .............................................................................................................3-7REMOVE QDR 4500A, OR SL, C-ARM (IF NECESSARY) ..................................................................................3-8PREPARING THE TABLE TOP FOR MOVING (SL only) ..................................................................................3-10MOVE UNIT TO DESTINATION (VERTICAL POSITION) ...............................................................................3-10MOVE UNIT TO DESTINATION (HORIZONTAL POSITION)..........................................................................3-11SET UP UNIT .........................................................................................................................................................3-13INSTALL QDR 4500A, OR QDR 4500SL, UPPER C-ARM.................................................................................3-15INSTALL QDR 4500W, OR QDR 4500C, C-ARM ...............................................................................................3-16INSTALL COMPUTER ..........................................................................................................................................3-17INSTALL CABLES.................................................................................................................................................3-17SAFETY PRECAUTIONS......................................................................................................................................3-18CHECK POWER LINE VOLTAGE .......................................................................................................................3-18

Measure Line Voltage .........................................................................................................................................3-18Measure Isolation Transformer Secondary Voltage ............................................................................................3-18

STARTING QDR SOFTWARE IN SERVICE MODE...........................................................................................3-19CHECK TUBE KV PEAK POTENTIAL................................................................................................................3-20CHECK TUBE CURRENT.....................................................................................................................................3-22CHECK BELT TENSION.......................................................................................................................................3-24ADJUST C-ARM Y BELT......................................................................................................................................3-24CALIBRATE MOTORS..........................................................................................................................................3-24CHECK X-RAY BEAM ALIGNMENT .................................................................................................................3-24CALIBRATE APERTURE (QDR 4500A AND SL)...............................................................................................3-24CHECK LASER POSITIONING OFFSET.............................................................................................................3-25ADJUST A/D GAIN CONTROL ............................................................................................................................3-25PERFORM DETECTOR FLATTENING................................................................................................................3-25PERFORM LATERAL ALIGNMENT TEST.........................................................................................................3-25MEASURE X-RAY DOSE TO PATIENT..............................................................................................................3-25CHECK HVPS/S (TANK) FOR RADIATION LEAKAGE....................................................................................3-26CALIBRATE FOR AREA, BMD AND BMC ........................................................................................................3-27TEST SCAN MODES .............................................................................................................................................3-27FINISH ASSEMBLING UNIT................................................................................................................................3-28MEASURE X-RAY SCATTER FROM PHANTOM..............................................................................................3-28PERFORM QC........................................................................................................................................................3-28RUN REPRODUCIBILITY TEST..........................................................................................................................3-29THE RADIATION MEASUREMENT REPORT ...................................................................................................3-30

SECTION 4 ALIGNMENT AND CALIBRATION .........................................................................4-1TABLE ALIGNMENT ..............................................................................................................................................4-1

Checking Table Alignment....................................................................................................................................4-1Aligning Table.......................................................................................................................................................4-1

Table Edge to T-Rail (“A” Dimension) Adjustment .........................................................................................4-1Front to Back T-Rail and Table Edge/Rail Gap Adjustment.............................................................................4-3

C-ARM PARALLELISM ADJUSTMENT (A and SL only).....................................................................................4-3X-RAY BEAM ALIGNMENT (A and SL only) .......................................................................................................4-4

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X-RAY BEAM ALIGNMENT (C and W only) ........................................................................................................4-8APERTURE CALIBRATION (A and SL only).........................................................................................................4-9MOTOR CALIBRATION .........................................................................................................................................4-9

MOTOR$TZ (QDR 4500A and SL)....................................................................................................................4-10MOTOR$AY (all QDR 4500 models).................................................................................................................4-12MOTOR$TY (QDR 4500A and W) ....................................................................................................................4-16MOTOR$TX (all QDR 4500 models) .................................................................................................................4-19MOTOR$AR (QDR 4500A and SL) ...................................................................................................................4-22

LASER POSITIONING OFFSET ADJUSTMENT.................................................................................................4-27A/D GAIN CONTROL ADJUSTMENT .................................................................................................................4-27DETECTOR FLATTENING ...................................................................................................................................4-28TABLE TOP RADIOGRAPHIC UNIFORMITY....................................................................................................4-30

Machines using Body Composition Analysis (BCA) ..........................................................................................4-30Machines using BMD Whole Body Analysis ......................................................................................................4-31

LATERAL ALIGNMENT TEST (QDR 4500A AND SL) ......................................................................................4-31CHECK PHANTOM VALUES...............................................................................................................................4-32AREA, BMD AND BMC CALIBRATION.............................................................................................................4-32

Scan Thickness Measurement & Calibration (QDR 4500A and SL)..................................................................4-33Scan Thickness Measurement & Calibration (QDR 4500W and C)....................................................................4-34Calibration of Area and BMC, for Array Scan Modes ........................................................................................4-35RECALYZE and Add Array AP Scans to the QC Database................................................................................4-36

SECTION 5 REMOVE AND REPLACE PROCEDURES ............................................................5-1RECOMMENDED TOOLS.......................................................................................................................................5-1ELECTRONICS TRAY FRUS..................................................................................................................................5-1

Electronics Tray Printed Circuit Boards................................................................................................................5-1C-Arm Y Belt ........................................................................................................................................................5-2C-Arm Y Motor or Gearcase .................................................................................................................................5-3C-Arm Y Encoder..................................................................................................................................................5-4

CONTROL PANEL AND TABLE Y FRUS .............................................................................................................5-4Control Panel.........................................................................................................................................................5-5PCBs Under Right-Side of the Table.....................................................................................................................5-5Table Y Belt ..........................................................................................................................................................5-6Table Y Motor or Gearcase ...................................................................................................................................5-6Table Y Encoder....................................................................................................................................................5-7

TABLE X FRUS........................................................................................................................................................5-8Table X Motor Controller PCB .............................................................................................................................5-8Table X Belt ..........................................................................................................................................................5-9Table X Motor or Gearcase .................................................................................................................................5-10Table X Encoder..................................................................................................................................................5-10

TABLE Z FRUS (A and SL only)............................................................................................................................5-11Pedestal................................................................................................................................................................5-11Linear Potentiometer (Encoder- Obsolete) ..........................................................................................................5-13The Linear Rotary String (Encoder) ....................................................................................................................5-13

Installation ......................................................................................................................................................5-13ARM R FRUS..........................................................................................................................................................5-15

Motor Controller Board.......................................................................................................................................5-15Arm R Belt ..........................................................................................................................................................5-16Arm R Motor, Gearcase, Encoder or Encoder Belt .............................................................................................5-16Gas Spring ...........................................................................................................................................................5-18

LOWER C-ARM FRUS ..........................................................................................................................................5-18C-Arm Interface Board ........................................................................................................................................5-18X-Ray Controller Assembly ................................................................................................................................5-18Filter Drum Assembly .........................................................................................................................................5-20Tank Assembly ....................................................................................................................................................5-21

UPPER C-ARM FRUS............................................................................................................................................5-23Integrator/Multiplexor Board ..............................................................................................................................5-23Detector Boards ...................................................................................................................................................5-24

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Laser Assembly ...................................................................................................................................................5-25REAR C-ARM FRUS..............................................................................................................................................5-26

Analog to Digital Converter Board .....................................................................................................................5-26POWER MODULE FRUS ......................................................................................................................................5-27

28 Volt Power Supply .........................................................................................................................................5-27±15 Volt Power Supply.......................................................................................................................................5-28Line Filter............................................................................................................................................................5-29Isolation Transformer ..........................................................................................................................................5-29Power Controller Board ......................................................................................................................................5-29

OPERATOR'S CONSOLE FRUS ...........................................................................................................................5-30APERTURE ASSEMBLY FRUS............................................................................................................................5-32

Aperture Stepper Motor ......................................................................................................................................5-32Aperture Motor PCB ...........................................................................................................................................5-33Aperture Position Belt.........................................................................................................................................5-33Rotary Potentiometer...........................................................................................................................................5-34

DRUM ASSEMBLY FRUS ....................................................................................................................................5-34Drum Encoder PCB.............................................................................................................................................5-34Drum Belts ..........................................................................................................................................................5-35Stepper Motor Assembly.....................................................................................................................................5-36Drum Bearings ....................................................................................................................................................5-37

REPLACING EMI CABLES...................................................................................................................................5-39FRU LISTS..............................................................................................................................................................5-41

Figure 5-1. Electronics Tray FRUs......................................................................................................................5-41Figure 5-2. Control Panel and Table Y FRUs .....................................................................................................5-41Figure 5-3. Left Side Table Y FRUs ...................................................................................................................5-41Figure 5-4. Table X FRUs...................................................................................................................................5-42Figure 5-5. Table Z FRUs ...................................................................................................................................5-42Figure 5-6. Installing the Rotary String Encoder.................................................................................................5-42Figure 5-7 C-Arm R FRUs (Outside View).........................................................................................................5-42Figure 5-8. C-Arm R FRUs (Inside View) ..........................................................................................................5-43Figure 5-9. Lower C-Arm FRUs .........................................................................................................................5-43Figure 5-11. Upper C-Arm FRUs........................................................................................................................5-43Figure 5-12. Detector Assembly Mounting .........................................................................................................5-43Figure 5-13. Laser Assembly...............................................................................................................................5-44Figure 5-14. Rear C-Arm FRUs ..........................................................................................................................5-44Figure 5-15. Power Module FRUs ......................................................................................................................5-44Figure 5-16. Power Control Panel FRUs.............................................................................................................5-44Figure 5-17. Operator's Console Assemblies.......................................................................................................5-45Figure 5-18. Computer Assemblies .....................................................................................................................5-46Figure 5-19. Aperture Assembly FRUs (QDR 4500A and SL) ...........................................................................5-46Figure 5-22. Front Drum Assembly FRUs ..........................................................................................................5-46Figure 5-23. Drum Outer Bearings......................................................................................................................5-47Figure 5-24. Drum Inner Bearings ......................................................................................................................5-47Cables..................................................................................................................................................................5-47Miscellaneous......................................................................................................................................................5-47Mobile .................................................................................................................................................................5-48Special Tools.......................................................................................................................................................5-48

SECTION 6 FAULT ISOLATION.................................................................................................6-1BEFORE STARTING ...............................................................................................................................................6-1SOFTWARE CONFIGURATION.............................................................................................................................6-1HARDWARE CONFIGURATION ...........................................................................................................................6-1POWER PROBLEMS ...............................................................................................................................................6-1MOTION PROBLEMS .............................................................................................................................................6-2CONTROL PANEL PROBLEMS.............................................................................................................................6-5DISPLAY PROBLEMS ............................................................................................................................................6-5

Vertical Stripe .......................................................................................................................................................6-5Horizontal Stripe ...................................................................................................................................................6-6

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Noise......................................................................................................................................................................6-6No Display.............................................................................................................................................................6-7

TARGETING/LASER PROBLEMS .........................................................................................................................6-8DATA COMMUNICATIONS PROBLEMS.............................................................................................................6-8AREA /BMD/BMC/CV SPECIFICATION PROBLEMS.........................................................................................6-9X-RAY PROBLEMS.................................................................................................................................................6-9

No X-Rays.............................................................................................................................................................6-9X-Ray Alignment Problems.................................................................................................................................6-10Detector Flattening Problems ..............................................................................................................................6-11

LASER PROBLEMS...............................................................................................................................................6-12OIL LEAKAGE .......................................................................................................................................................6-13

The Torque Specifications...................................................................................................................................6-13Tank Top Cover Components and Screw Location .............................................................................................6-13Tightening the Lexan Cup Screws.......................................................................................................................6-14Tightening the Bladder Gasket Screws................................................................................................................6-14Tightening the Transformer Seal Screws.............................................................................................................6-14Tightening the Tank Cover Gasket Screws..........................................................................................................6-15

MISCELLANEOUS PROBLEMS ..........................................................................................................................6-16

SECTION 7 PREVENTIVE MAINTENANCE...............................................................................7-1CUSTOMER PREVENTIVE MAINTENANCE ......................................................................................................7-1FIELD SERVICE PREVENTIVE MAINTENANCE ...............................................................................................7-1

Guide Rail and Bearing Maintenance....................................................................................................................7-3

SECTION 8 PCB SUMMARY INFORMATION ...........................................................................8-1Power Distribution ................................................................................................................................................8-1ADC ......................................................................................................................................................................8-1Signal Distribution ................................................................................................................................................8-2Communications Controller ..................................................................................................................................8-2Detector Array Assembly.......................................................................................................................................8-3TZ Drive ................................................................................................................................................................8-3Stepper Motor Controller ......................................................................................................................................8-4Control Panel Controller .......................................................................................................................................8-4

SECTION 9 SOFTWARE TOOLS...............................................................................................9-1X-Ray Survey ........................................................................................................................................................9-1

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TABLE OF FIGURES

Figure 1-1. QDR 4500 ................................................................................................................1-2Figure 1-2. Q Scan Plot .................................................................................................................1-3Figure 1-3. QDR 4500 Block Diagram (Operator's Console) .......................................................1-4Figure 1-4. QDR 4500 Block Diagram (Scanner Unit).................................................................1-5Figure 1-5. QDR 4500 Block Diagram (C-Arm Subsystem) ........................................................1-6Figure 2-1. Communications Controller Board/Distribution Board Interconnection Diagram ....2-3Figure 2-2. Distribution Board High Level Interconnection Diagram..........................................2-4Figure 2-3. Distribution Board/Motor Controller Board Interconnection Diagram .....................2-6Figure 2-4. Distribution Board/TZ Drive Board Interconnection Diagram..................................2-9Figure 2-5. Control Panel Controller Interconnection Diagram ...............................................2-12Figure 2-6. Distribution Board/C-Arm Interface Board Interconnection Diagram.....................2-16Figure 2-7. C-Arm Interface Board High Level Interconnection Diagram................................2-18Figure 2-8. C-Arm Interface Board/X-Ray Controller Assembly Interconnection Diagram....2-19Figure 2-9. X-Ray Controller Assembly High-Level Interconnection Diagram........................2-21Figure 2-10. Low Voltage Power Supply Board Interconnections ............................................2-22Figure 2-11. PFR Substitution Board/I/O and Logic Board Interconnection Diagram .............2-24Figure 2-12. I/O and Logic Board/H-Bridge Board Interconnection Diagram..........................2-24Figure 2-13. I/O and Logic Board/Duty Cycle Driver Board Interconnection Diagram ...........2-25Figure 2-14. H-Bridge Board/Duty Cycle Driver Board Interconnection Diagram...................2-25Figure 2-15. Integrator/Multiplexor Board/Solid State Detector Boards Interconnection Diagram2-27Figure 2-16. Analog Digital Converter Board/Integrator Multiplexor Board Interconnection

Diagram..................................................................................................................2-29Figure 2-17. C-Arm Interface Board/Analog/Digital Converter Board Interconnection Diagram2-31Figure 2-18. Power Module Block Diagram..............................................................................2-33Figure 3-1. Room Layout (4500A)................................................................................................3-2Figure 3-2. System Dimensions (4500SL) ....................................................................................3-3Figure 3-3. System Dimensions (4500W).....................................................................................3-3Figure 3-4. System Dimensions (4500C) ......................................................................................3-4Figure 3-5. Crated Unit (QDR 4500A and QDR 4500SL) ...........................................................3-5Figure 3-6. Uncrated Unit (QDR 4500A and QDR 4500 SL) ......................................................3-7Figure 3-7. Table X Drive.............................................................................................................3-8Figure 3-8. Tipping Unit ...............................................................................................................3-9Figure 3-9. Moving and Tilting the Unit Down..........................................................................3-11Figure 3-10. Auxiliary Horizontal Caster Installation ................................................................3-12Figure 3-11. Shipping Bracket Locations (QDR 4500A and SL) ...............................................3-13Figure 3-12. Shipping Bracket Locations (QDR 4500A and SL) ...............................................3-14Figure 3-13. Shipping Bracket Locations (QDR 4500W and C) ................................................3-14Figure 3-14. Shipping Bracket Location (QDR 4500W and C)..................................................3-15Figure 3-15. Repositioning the Belt Tensioning Mechanism .....................................................3-16Figure 3-16. Isolation Transformer Taps ....................................................................................3-17Figure 3-17. Peak Potential Mode 4............................................................................................3-21Figure 3-18. Peak Potential Mode 3............................................................................................3-21Figure 3-19. Tube Current Mode 1 .............................................................................................3-23

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Figure 3-20. Tube Current Mode 3 .............................................................................................3-23Figure 3-21. Leakage Test Shield (099-0566) ............................................................................3-27Figure 4-1. Table Alignment.........................................................................................................4-2Figure 4-2. Pedestal (covers removed)..........................................................................................4-3Figure 4-3. X-Ray Alignment Fixture (010-0923)........................................................................4-4Figure 4-4. Inserting The X-Ray Alignment Fixture ....................................................................4-5Figure 4-5. The Alignment Fixture Properly Installed..................................................................4-6Figure 4-6. Filter Drum Adjustments - Top View ........................................................................4-6Figure 4-7. Array Assembly - Top View, Partial ..........................................................................4-7Figure 5-1. Electronics Tray FRUs ...............................................................................................5-3Figure 5-2. Control Panel and Table Y FRUs...............................................................................5-5Figure 5-3. Left Side Table Y FRUs.............................................................................................5-7Figure 5-4. Table X FRUs.............................................................................................................5-9Figure 5-5. Table Z FRUs ...........................................................................................................5-12Figure 5-6. Installing the Rotary String Encoder ........................................................................5-14Figure 5-7 C-Arm R FRUs (Outside View) ................................................................................5-15Figure 5-8. C-Arm R FRUs (Inside View)..................................................................................5-17Figure 5-9. Lower C-Arm FRUs .................................................................................................5-20Figure 5-10. Top View of Tank ..................................................................................................5-22Figure 5-11. Upper C-Arm FRUs................................................................................................5-24Figure 5-12. Detector Assembly Mounting.................................................................................5-25Figure 5-13. Laser Assembly ......................................................................................................5-26Figure 5-14. Rear C-Arm FRUs ..................................................................................................5-27Figure 5-15. Power Module FRUs ..............................................................................................5-28Figure 5-16. Power Control Panel FRUs ....................................................................................5-30Figure 5-17. Operator's Console Assemblies ..............................................................................5-31Figure 5-18. Computer Assemblies.............................................................................................5-32Figure 5-19. Aperture Assembly FRUs (QDR 4500A and SL) ..................................................5-33Figure 5-20. Aperture Assembly Removal (QDR 4500A and SL) .............................................5-35Figure 5-21. Rear Drum Assembly FRUs ...................................................................................5-36Figure 5-22. Front Drum Assembly FRUs..................................................................................5-37Figure 5-23. Drum Outer Bearings .............................................................................................5-38Figure 5-24. Drum Inner Bearings ..............................................................................................5-39Figure 5-25. The EMI Compliance Cable...................................................................................5-40Figure 6-1. Scanner Motion Directions.........................................................................................6-3Figure 6-2. Checking C-Arm Parallelism....................................................................................6-10Figure 6-3 Tank Assembly Top view..........................................................................................6-13Figure 6-4 Lexan Cup Screw Tightening Order .........................................................................6-14Figure 6-5. Bladder Gasket Screws.............................................................................................6-14Figure 6-6. Transformer Screws .................................................................................................6-15Figure 6-7. Tank Cover Gasket ...................................................................................................6-16Figure 7-1. Guide Bearing and Rail ..............................................................................................7-3Figure 9-1. X-RAY SURVEY Screen−X-Rays OFF....................................................................9-2Figure 9-2. X-RAY SURVEY Screen−X-Rays ON......................................................................9-2Figure 9-3. X-RAY SURVEY Screen Settings.............................................................................9-3

1-1

SECTION 1 INTRODUCTION

SYSTEM OVERVIEWThe Hologic QDR 4500 X-ray Bone Densitometer (Figure 1-1) estimates the bone mineralcontent (BMC) and bone mineral density (BMD) of selected areas of the body, or of the entireskeleton. It does so using X-rays of two different energy levels. This dual-energy scheme allowssoft tissue within the selected area to be subtracted out, leaving only bone to be scanned andestimated.

Note: This manual uses "QDR 4500" to refer to all models in the QDR 4500 QDR for Windowsseries systems. Information presented in this manual, that applies only to a particularmodel, or models, will be noted as such.

The patient lies face up on the table and, with the aid of a cross-hair laser, the operator positionsthe scanning arm over the region of interest. After entering patient data and selecting the typeand size of scan desired, the operator initiates the scan with a single keystroke.

The operator is not required to select technique factors, as tube current and voltage are pre-selected and fixed. Since testing is performed by fan beam method rather than by flooding thearea as in conventional radiography, the scanning time is a function of the dimensions of the areato be measured, the desired resolution and the desired precision.

BMC results are expressed in grams of calcium hydroxyapatite, and BMD is reported ingrams/cm2 of the same compound.

Note: In most cases, no additional shielding is necessary for patient, operator or room, and theQDR 4500 QDR for Windows can be placed in any convenient non-shielded examinationroom. Contact your state regulatory agency for details about additional shieldingrequirements, if any.

The QDR 4500 QDR for Windows employs a patented Automatic Internal Reference System,which continuously calibrates the machine to eliminate the effects of variations in temperature,tube flux, etc. No daily calibration is required. The daily scanning of a quality control phantom isrequired to provide assurance that the system is functioning correctly, and to aid in the detectionof any long-term drift.

The X-ray scans produced by the QDR 4500 QDR for Windows, and displayed on the monitor,are intended only to locate anatomical sites for measurement, and to assure the operator that themachine is operating properly. They are not intended as a substitute for conventional film-baseddiagnostic scans.

QDR® 4500 Technical Manual

1-2

Scanner Unit

Operator's Console

Figure 1-1. QDR 4500

X-RAY SCANNING THEORYAn X-ray source, consisting of a generator and tube in a common, shielded enclosure, is mountedbeneath the patient. It generates a narrow, tightly collimated, fan shaped beam of X-rays whichalternate, at power line frequency, between 100kVp and 140kVp. The source is at one end of aC-arm. At the other end, above the patient, is a crystal/solid state detector. During a scan, the C-arm and table move under computer control to guide the beam over the desired scan area.

Before passing through the patient, the beam is filtered through a rotating drum, in whichalternating segments have radio-opacities equivalent to tissue, bone and air. When finallyintercepted by the detector, the beam contains information about the X-ray absorbingcharacteristics of both the patient and the calibration materials in the filter drum. An A/Dconverter, fed by the detector, supplies a complex digital signal to the computer, which uses thatsignal both to construct the screen display and as the basis for its computations of BMC andBMD.

The QDR 4500 computer algorithm is based on the principle that bone attenuates the X-ray beamdifferently at high and low energies. The bone mineral content of any sample point can becomputed from:

Q = L - kH

where H and L are the logarithms of the sample attenuation at high (140kVp) and low (100kVp)energies, respectively, and the constant k depends on the tissue attenuation characteristics of thebeam. In the QDR 4500, k is continuously measured using the “tissue” segment in the filterwheel.

Section 1 - Introduction

1-3

The program works in the following manner:

1. Load preliminary scan and obtain regions of interest from operator.

2. Estimate k as an average value of:

k = [Ltissue - Lair] / [Htissue - Hair]

where Ltissue indicates a low-energy measurement with tissue-equivalent material

interposed by the filter drum, and Lair, Htissue and Hair are similarly defined.

Note: The subscript "air" designates the filter drum segment that is empty (i.e., contains neither

bone- nor tissue-equivalent material).

3. Using this value of k, calculate Q for each point scanned using the formula given above(Q = L - kH). This array of Q values constitutes a "Q scan". Displays the Q scan.

4. Compile a histogram of the Q values. Because a large portion of the scan contains softtissue only, this histogram will have a large peak. Choose a threshold value just abovethis peak, and apply that value to discriminate, point by point in the Q scan, between"bone" points (whose Q is above the threshold) and "non-bone" points (whose Q isbelow the threshold).

Figure 1-2. Q Scan Plot

5. Use the "non-bone" points to calculate a baseline value for each scan line. Using thesepoints, form a new histogram and repeat steps 4 and 5 until the results converge.

6. Smooth the segment boundaries to eliminate isolated noise-generated "bone" points.

7. Display the "bone" and "non-bone" points for operator approval.

8. Determine the constant of proportionality (d0) that relates the Q values to actual BMC(grams). That constant is determined by measuring how much Q shifts when bone-equivalent material is interposed by the filter drum.

9. Calculate the total bone mineral values by adding up the Q values for all "bone" pointsin each region of interest (e.g., each vertebra), and multiplying by d0.

10. Determine the bone areas by counting the number of "bone" points in each region ofinterest.

11. Calculate bone mineral density as:


1-4

BMD = BMC / area

12. Display the calculated results and print the report.

FUNCTIONAL OVERVIEWThis section provides a block diagram of the QDR 4500 system along with a brief functionaloverview description of each block. A detailed functional description along with interconnectiondiagrams and interconnection descriptions is provided in Section 2.

KEYBOARD

MOUSE

DISPLAYTERMINAL

PRINTER

POWERSTRIP

COMMUNICATIONSCONTROLLER

TO/FROMINSTRUMENTDISTRIBUTION(FIGURE 1.4)

POWERASSEMBLY

15/24V EMERGENCY

28V DC

TO X-RAY CONTROLLER (FIGURE 1.5)

AC IN

VGA

SCSI INTERFACE

OPTICAL/JAZDISK(Option)

Computer

AC

ACAC

MODEM PHONEJACK

TO/FROM LEFT/RIGHT PEDESTAL DRIVE (FIGURE 1.4)

Figure 1-3. QDR 4500 Block Diagram (Operator's Console)


1-5

DISTRIBUTION

CONTROLPANEL

CONTROLLER

TZ DRIVEMOTOR

CONTROLLER

TX STEPPERMOTORDRIVER

TY STEPPERMOTORDRIVER

AR STEPPERMOTORDRIVER

AY STEPPERMOTORDRIVER

PEDESTAL LEFTMOTOR AND

POSITION ENCODER

C_ARM CARRIAGEMOTOR AND

POSITION ENCODER

C_ARM ROTATIONMOTOR AND

POSITION ENCODER

PEDESTAL RIGHTMOTOR AND

POSITION ENCODER

TABLE LEFT/RIGHTMOTOR AND

POSITION ENCODER

TABLE IN/OUTMOTOR AND

POSITION ENCODER

CONTROL PANEL

TO/FROM C-ARM INTERFACE (FIGURE 1-5)

TO/FROMCOMMUNICATIONCONTROLLER

15/24VEMERGENCY

LEFT/RIGHT PEDESTAL

28V DC

TO/FROMPOWERMODULE

Figure 1-4. QDR 4500 Block Diagram (Scanner Unit)


1-6

C-ARMINTERFACE

ANALOG TODIGITAL

CONVERTER

INTEGRATORMULTIPLEXOR

SILICONDETECTORS

X_RAYSOURCE

UNIT

X_RAYCONTROLLER

APERTUREMOTOR AND

SENSOR

LASERASSEMBLY

DRUMMOTOR AND

ENCODER PICKUP

TO/FROMDISTRIBUTION

FROM POWER MODULE

Figure 1-5. QDR 4500 Block Diagram (C-Arm Subsystem)

Block Description

Computer Controls and commands all QDR 4500 hardware modules.

CommunicationsController

Controls the flow of commands to and from the Scanner modules via thecommunications bus.

Distribution Board Provides the interconnections between the QDR 4500 Operator's Consoleand the Scanner.

Control PanelController

Interfaces the Scanner’s Control Panel to the Operator's Consolecomputer software.

Control Panel Provides switches (with visual indicators) for moving the Scanner’s C-Arm and Patient Table. Also provides an Emergency Stop switch.

TZ Drive MotorController

Controls the motion of the Patient’s Table left and right pedestal motorsbased on commands from the computer software.


1-7

Table Up/DownMotor and PositionEncoder

Raises or lowers the Patient Table and provides position monitoring.

TX Stepper MotorDriver

Controls the motion of the Patient’s Table in and out motor based oncommands from the computer software.

Table In/Out Motorand PositionEncoder

Moves the Patient Table in and out and provides position monitoring.

TY Stepper MotorDriver

Controls the motion of the Patient’s Table left and right motor based oncommands from the computer software.

Table Left/RightMotor and PositionEncoder

Moves the Patient Table left and right and provides position monitoring.

AR Stepper MotorDriver

Controls the motion of the C-Arm rotation motor based on commandsfrom the computer software.

C-Arm RotationMotor and PositionEncoder

Rotates the C-Arm and provides position monitoring.

AY Stepper MotorDriver

Controls the motion of the C-Arm left and right motor based oncommands from the computer software.

C-Arm AY Motorand PositionEncoder

Moves the C-Arm left and right and provides position monitoring.

C-Arm Interface Controls the Aperture and Filter Drum motors, generates timing signalsfor the X-Ray Controller and the Data Acquisition System, and providespower to the Positioning Laser.

X-Ray Controller Controls the operation of the X-ray source.

X-Ray Source Unit Generates the X-ray beam.

Solid State Detectors Converts the X-rays into electrical signals.

Integrator/Multiplexor

Integrates the signals from the Solid State Detectors and applies them tothe Analog to Digital Converter.

Analog to DigitalConverter

Converts the analog signals from the Integrator/Multiplexor to a digitalformat.

Positioning Laser Provides a laser beam to assist in positioning the patient on the PatientTable.


1-8

PRODUCT SPECIFICATIONSSPECIFICATION MODEL DEFINITION

Scanning Method: A,SL Multidetector array, Indexing table, and motorized C-arm

W,C Multidetector array, Indexing table, and Arm

X-ray System: AllSwitched Pulse Dual-Energy X-ray tube, operating at 100 and140kV, 5mA avg. at 50% duty cycle, 2.5mA avg. at 25% duty cycle,30s maximum, Tungsten target

Detector System:A

216 multichannel detector consisting of CdWO4 scintillators

coupled to Silicon diodes

SL128 multichannel detector consisting of CdWO4 scintillators

coupled to Silicon diodes

C,W64 multichannel detector consisting of CdWO4 scintillators coupled

to Silicon diodes

Scanning Sites:A

Lumbar spine (in AP and lateral projections), proximal femur (hip),and whole body

SL Lumbar spine (in AP and lateral projections), proximal femur (hip)

W Lumbar spine, proximal femur (hip), and whole body

C Lumbar spine, proximal femur (hip)

Scan Region: A,W 195cm (76.77") x 65cm (25.59")

SL 96cm (38") x 65cm (25.59")

C 96cm (38") x 51cm (20")

Scatter Radiation:

All

Less than 10µGy/h (1mrad/h) at 2m (79 in.) from the center of theX-ray beam for all scans except images, which is less than10µGy/h (1mrad/h) at 3.5m (138 in.) from the center of the X-raybeam.

LeakageRadiation:

AllThe QDR-4500 meets the requirements of 21 CFR 1020.30(k) forleakage from the X-ray source

External ShieldingRequirement:

All Contact state regulatory agency.

Calibration: AllSelf Calibrating using HOLOGIC Automatic Internal ReferenceSystem. Operator calibration NOT required.

System Weight: Scanner Console

A 365kg 800lb

SL 365kg 800lb

W 310kg 680lb(installed)

C 295kg 650lb

68kg 150lb

System

A 660kg 1450lb

SL 660kg 1450lb

W 622kg 1370lb

(shipping)

C 610kg 1340lb


1-9

SPECIFICATION MODEL DEFINITION

OperatingTemperature:

All 15o - 32o C (60o - 90o F)

Humidity: All 20 - 80% relative Humidity, non-condensing

Footprint: Length Width Height

m inches m inches m inches

C-arm notrotated, table notextended

A 2.02 79.5 1.40 55 1.42 56

C-arm rotated,table extended A 3.02 119 1.50 59 1.42 56

C-arm not rotated SL 2.02 79.5 1.40 55 1.42 56

C-arm rotated SL 2.02 79.5 1.50 59 1.42 56

table extended W 3.02 119 1.50 59 1.42 56

table notextended W 2.02 79.5 1.22 48 1.42 56

C 2.02 79.5 1.40 55 1.42 56

Average HeatLoad:

ALL 1000w (3400 BTU/hr)

A,SL Adjustable, 71cm (28") from floor when scanning in AP modePatient TableHeight: W,C 71cm (28”)

Positioning Laser: AllLaser Diode (


1-10

BMD Precision:

SCAN TIME DOSE

EXAM MODEL (seconds) in vivo PRECISION mGy mrad

AP Spine Array All 60 1.0% 0.20 20.0

AP Spine Fast All 30 1.0% 0.10 10.0

AP Spine High Definition A,SL 120 1.0% 0.20 20.0

AP Spine Turbo A,SL 10 1.5% 0.07 7.0

W,C 15 1.5% 0.05 5.0

Forearm A,SL 30 1.0% 0.05 5.0

W,C 30 1.0% 0.10 10.0

Hip Array All 60 1.0% 0.20 20.0

Hip Fast All 30 1.0% 0.10 10.0

Hip High Definition A,SL 120 1.0% 0.20 20.0

Hip Turbo A,SL 10 1.5% 0.07 7.0

W,C 15 1.5% 0.05 5.0

Lateral Spine Array A,SL 240 1.0% 0.70 70.0

Lateral Spine Fast A,SL 120 1.0% 0.35 35.0

Lateral Spine High Def. A,SL 240 1.0% 0.70 70.0

Whole Body A 180 1.0% 0.01 1.0

W 407 1.0% 0.015 1.5

Duty Cycle:

A50% for all scan modes except Whole Body100% for Whole Body scans

SL,W,C 50% for all Scan Modes

Leakage Technique Factors

The leakage technique factors for all models of QDR 4500’s are the same. It is the maximumcontinuous current at the maximum peak potential. This is X-ray mode #3. Peak potential140/100kVp. (dual energy), current 10mA peak 25% duty cycle or 2.5mA average.

Minimum Beam Filtration

The minimum filtration permanently in the beam is 3.7mm Al equivalent @80kV.


1-11

Measured Half Value Layer (HVL) At Different Operating Potentials

Measured operating potential Measured Half Value Layer

QDR4500A/SL

80kV 3.7mm Al equivalent



QDR4500C/W




Line Voltage and Maximum Line Current

PowerRequirements: All

100VAC 16A 50/60Hz, Max apparent resistance = 0.32 ohm120VAC 14A 50/60Hz, Max apparent resistance = 0.32 ohm230VAC 8A 50/60Hz, Max apparent resistance = 1.28 ohm

Technique Factors for Maximum Line Current

Peak Potential 140kVp

Tube Current 10mA peak, 50% duty factor or 5mA average.

Maximum Deviation

The maximum deviation from the pre-indication given by labeled technique factor controlsettings or indicators are as follows:

Peak Potential: +/- 15%

Current: +/- 40%

Time : +/- 10%

Measurement Criteria for Technique Factors

The measurement criteria of the technique factors is as follows:

Peak Potential: The voltage peak is measured with an oscilloscope. Voltage is a square pulse.Peak is defined as the peak voltage of the 4 millisecond pulse shape, notcounting any initial overshoot.

Current: Current is measured with an oscilloscope on the last millisecond of the 4millisecond pulse.

Time: Time of each pulse is measured with an oscilloscope and defined as the timebetween 50% rise and fall times of the peak potential pulse. Time of the scanis measured by counting the number of AC line pulses from the start to theend. X-ray pulses are synchronous with the AC line.

2-1

SECTION 2 FUNCTIONAL DESCRIPTION

This section provides a detailed functional description along with interconnection diagrams anddescriptions of the Hologic QDR 4500. Refer to Section 1 for a block diagram and a brieffunctional description of each block.

COMPUTERThe QDR 4500 Scanner interfaces to an ISA Bus computer to control table and C-arm movementand X-ray generation, perform all necessary calculations, and manage patient and QC databaseinformation.

The computer is a Pentium-based (or higher) PC compatible that comes equipped with 3.5-inchfloppy disk and hard disk drives, keyboard, color monitor, and an optional Iomega 1GB JAZdrive. For details pertaining to the computer and its associated components, please refer to thedocumentation shipped with each unit.

COMMUNICATIONS CONTROLLER BOARDThe Communications Controller board handles all the communications between the Computerand the Scanner’s C-Arm and Table assemblies. The board resides in one of the computerinternal slots and interfaces with the computer via the computer's I/O bus. It connects to theScanner’s Distribution board through a 50-conductor ribbon cable. This cable contains twoindependent communications links (one asynchronous and one synchronous) and additionalsystem control signals. Each signal requires a pair of conductors for differential (RS422) noiseimmunity.

The asynchronous communications link communicates with the Motor Controller boards (TX,TY, AY and AR), the TZ Drive board, the C-Arm Interface board, and the Control PanelController board. The synchronous communications link communicates with the DataAcquisition System (DAS).

Interface Connections

Table 2-1 describes the interconnections between the Communications Controller board and theDistribution board. The table also identifies the interconnection connector and pin assignments.

Figure 2-1 shows the interconnections between the Communications Controller board and theDistribution board.


2-2

Table 2-1. Communications Controller Board/Distribution BoardInterconnection Descriptions

Signal Pair Description CC1

Pin Dist2

Pin

ATD+ATD-

Asynchronous data to the Scanner. JP1-2JP1-27

JP10-3JP10-4

STD+STD-

Synchronous data to the Scanner. JP1-28JP1-4

JP10-6JP10-7

STCLK+STCLK-

Synchronous data clock from Communications Controllerboard to Distribution board. Synchronizes data to theScanner.

JP1-5JP1-30

JP10-9JP10-10

STFRM+STFRM-

Synchronous data frame from Communications Controllerboard to Distribution board.

JP1-31JP1-7

JP10-12JP10-13

ARD+ARD-

Asynchronous Data from the Scanner. JP1-8JJP1-33

JP10-15JP10-16

SRD+SRD-

Synchronous Data from the Scanner. JP1-34JP1-10

JP10-18JP10-19

SRCLK+SRCLK-

Synchronous data clock from Communications Controllerboard to Distribution board. Synchronizes data from theScanner.

JP1-11JP1-36

JP10-21JP10-22

SRFRM+SRFRM-

Synchronous data frame from Distribution board toCommunications Controller board.

JP1-37JP1-13

JP10-24JP10-25

EMERGENCY_IN+EMERGENCY_IN-

Signals an emergency condition. Generated by the C-ArmInterface board.

JP1-14JP1-39

JP10-27JP10-28

ZEROX+ZEROX-

AC line zero-crossing signal used for system widesynchronization. Generated by the C-Arm Interface board.

JP1-40JP1-16

JP10-30JP10-31

INTEGRATE+INTERGATE-

Synchronous signal for Detector Integrate period.Generated by the C-Arm Interface board.

JP1-17JP1-42

JP10-33JP10-34

SYSRESET+SYSRESET-

Resets the Scanner controllers. JP1-20JP1-45

JP10-39JP10-40

EMERGENCY+EMERGENCY-

Removes power from the Scanner’s motor drivers and theX-ray system

JP1-49JP1-25

JP10-48JP10-49

Note: 1. CC = Communications Controller board.2. Dist = Distribution board.

Section 2 - Functional Description

2-3

ATD+, ATD-

STD+, STD-

STCLK+, STCLK-

STFRM+, STFRM-

ARD+, ARD-

SRD+, SRD-

SRCLK+, SRCLK-

SRFRM+, SRFRM-

EMERGENCY_IN+, EMERGENCY_IN-

ZEROX+, ZEROX-

INTEGRATE+, INTEGRATE-

SYSRESET+, SYSRESET-

EMERGENCY+, EMERGENCY-

DISTRIBUTIONBOARD


BOARD

Figure 2-1. Communications Controller Board/Distribution BoardInterconnection Diagram

DISTRIBUTION BOARDThe Distribution board provides interconnections between the QDR 4500 Operator's Console andthe Scanner. It passes several signal and power lines from the Operator's Console directly to theC-Arm Interface module. It also provides buffering and individual drivers and receivers forvarious signal lines to and from individual Scanner modules and the Communications Controller.The Distribution board is located in the Electronics Tray in the base of the Scanner.

Three cables connect the Operator's Console to the Distribution board. One cable connects thecommunications buss to the Communications Controller located in the Operator's Consolecomputer. Two cables connect to the Operator's Console Power Module. These two cablesconnect power to the Distribution board and connect the X-Ray On and Emergency signal linesto the Power Module.

Eight cables connect the Distribution board to the various Scanner boards. Four cables connectto the four Motor Controller boards (Table X, Table Y, Arm R, and Arm Y). Two (one signaland one power) connect to the C-Arm Interface board. One connects to the TZ Drive board. Inaddition, one connects to the Scanner's Control Panel Controller board.

The Distribution board has provision for three jumpers that can be installed to override theEMERGENCY signal lines when trouble-shooting.

Power

The Distribution board receives +28, +24 and +/-15VDC from the Operator's Console PowerModule. The +28VDC is applied through four individual circuit breakers to the Table X, TableY, Arm R, and Arm Y Motor Controller boards. The +24 and +/-15VDC are passed to the C-Arm Interface board. +24VDC is also applied through a circuit breaker to the Table Z Driveboard. It is also reduced to +7 and + 5VDC by regulators to power op-amplifiers and analogswitches located on this board. The + 7VDC is passed to the Table Z Drive and Control PanelController boards. The + 5VDC powers the digital section of the Distribution board. The +28and +24VDC power supplies are not closely regulated and their outputs may range from +24V to+ 35V under normal conditions.


2-4

Note: +7VDC may measure anywhere from +6.25VDC to +7.25VDC. This is true everywhere+7VDC is shown in this manual.

Six green LEDs indicate the status of the +28, +24, +15, -15, +7 and +5VDC (ON indicates therespective voltage is present). Five red LEDs indicate the status of the five circuit breakersapplying voltage to the motor drivers/controller. ON indicates the circuit breaker has detected anover-current condition.


Figure 2-2 shows boards that connect to the Distribution board.

DISTRIBUTIONBOARD

C-ARMINTERFACE

BOARD

CONTROL PANELCONTROLLER

BOARD

TZDRIVE

BOARD

TX MOTORCONTROLLER

BOARD

TY MOTORCONTROLLER

BOARD

AR MOTORCONTROLLER

BOARD

AY MOTORCONTROLLER

BOARD


BOARD

+24 VDC, +/-15VDC,EMERGENCY

SIGNAL LINES

+28 VDC

OPERATOR’SCONSOLE

COMPUTER

OPERATOR’SCONSOLE

POWER MODULE

INSTRUMENT

Figure 2-2. Distribution Board High Level Interconnection Diagram


2-5

MOTOR CONTROLLER BOARDThe Motor Controller board is a microprocessor controlled power driver circuit for use with atwo-coil bipolar stepper motor. It receives high level commands through the Distribution Boardfrom the host computer, and applies 28-volt pulses to the stepper motor windings. The QDR4500 uses four identical Motor Controller boards to control and drive the Table X (Table In/Out),Table Y (Table Left/Right), C-Arm Rotate, and C-Arm Y (C-Arm Left/Right) stepper motors.The motor windings are driven by two integrated H-bridges. These integrated circuits provideinternal level conversion and power limiting. Their logic level control inputs are driven from astepper motor control microcircuit that receives commands from the microprocessor. The controlcircuit senses the current in the motor windings and adjusts the duty cycle of the applied voltagein such a way as to limit the maximum motor current. The maximum value is determined by an8-bit control word at a Digital to Analog Converter.

Each Motor Controller board monitors the position of its respective mechanism using a signalreceived from an associated Position Encoder connected to the mechanism. The Position Encoderis a precision potentiometer that divides a +/-3V reference source into a sense amplifier inproportion to the position of the mechanism driven by the motor. The sense amplifier output isconverted to digital code that provides position feedback to the microprocessor.

The Motor Controller boards receive movement commands from the QDR 4500 computer via thecommunications bus. Each Motor Controller board contains an ID switch and four statusindicators (LEDs). The ID switch is a 16-position rotary encoded switch (SW1) that is readduring system initialization to determine the Motor Controller board's address for communicatingwith the QDR 4500 computer. ID switch settings for the four Motor Controller boards are asfollows:

Table X drive 4

Table Y drives 5

C-Arm Rotate drive 6

C-Arm Y drive 7

The four red status LEDs provide visual indications of motor drive power on, Stepper CPUactive, motor drive direction, and motor step pulses.

The Motor Controller board also has provision (JP2) for connecting limit switches to inhibitmotor operation when the mechanism goes beyond established mechanical limits. This feature isnot used in the QDR 4500 and therefore no cable is connected to JP2.

Power

Power input to the Motor Controller board is +28VDC. This voltage provides the motor drivepower and is converted down to +5VDC for use by logic circuits on the board. The +5VDC isalso converted to -5VDC. Two green LEDs provide visual indication of the power present on theMotor Controller board.


2-6


Figure 2-3 shows the interconnections between the Distribution board, the Motor Controllerboards, the Stepper Motors, and the Position Encoders. Table 2-1 describes the interconnectionsbetween the Distribution board and the Motor Controller. Table 2-3 describes theinterconnections between each Motor Controller and its respective stepper motor and positionencoder. The tables also identify the interconnection connector and pin assignments.

ARD+, ARD-

ATD+, ATD-

SYSRESET+, SYSRESET-

+28V

28V_RET

( )( )( )( )

+REF

( )-REF

MOTORCONTROLLER

STEPPERMOTOR

To/FromDistribution Board

POSITIONENCODER

Figure 2-3. Distribution Board/Motor Controller BoardInterconnection Diagram

Table 2-2. Distribution Board/Motor Controller BoardInterconnection Descriptions

Signal Description TableX

TableY

C-ArmRotate

C-ArmY

Pin(s)

ARD+ARD-

Asynchronous Receive Data. JP7 JP5 JP8 JP11 1112

ATD+ATD-

Asynchronous Transmit Data. JP7 JP5 JP8 JP11 1415

SYSRST+SYSRST-

System Reset. Resets the MotorController board.

JP7 JP5 JP8 JP11 1718

28V28V_RET

DC power for the MotorController board.

JP7 JP5 JP8 JP11 2,3,4,51,6,7,8


2-7

Table 2-3. Motor Controller Board/Stepper Motor and Position EncoderInterconnection Descriptions

Signal Description Pin

(No label) Motor drive signals (4). JP5-1 - JP5-4

+REF Precision positive voltage to position potentiometer. JP3-1

(No label) Position encoder wiper return voltage. JP3-3

-REF Precision negative voltage to position potentiometer. JP3-5

TZ DRIVE BOARDThe TZ Drive Board is a microprocessor controlled power driver circuit for the two pedestalmotors, which raise and lower the patient table in the QDR 4500A and SL. This board is locatedin the electronics tray in the bottom of the Scanner base assembly.

The TZ Drive board communicates with the communications controller, via the Distributionboard, to drive the pedestal motors under computer control. Manual raising of the pedestal maybe required in case of an emergency. In this case, manual control is provided through the Tableswitch of the Scanner’s Operator Control Panel.

The TZ Drive board monitors the position of each pedestal using signals received from anassociated Position Encoder connected to the respective pedestal.

Service Switches

The TZ Drive board contains four service switches used during replacement of a defectivepedestal or Position Encoder. Table 2-4 describes these switches and their respective functions.

CAUTION: The TZ drive motors are designed to run at a 5% duty cycle. If the motors overheat,the built-in thermal cutouts may trip and cause the motors to stop functioning. Ifthis happens, you must wait about 20 minutes before functionality is restored.

Table 2-4. TZ Drive Service Switches

Switch Function

Mode(Normal/Service)

Determines whether the TZ Drive is in Normal or Service operation.

Direction (Up/Down) When the TZ drive is in Service mode, determines the direction of pedestalmovement (not active in normal mode).

Left When the TZ drive is in Service mode, moves the left pedestal in thedirection specified by the Direction switch (not active in normal mode).


2-8

Right When the TZ drive is in Service mode, moves the right pedestal in thedirection specified by the Direction switch (not active in normal mode).

Reset Resets the board after manual operation. The TZ Drive board must bereset after any manual operation.

Power

Power input to the TZ Drive board is +24VDC from the Distribution board and 240VAC fromthe Operator's Console Power Module. +24VDC powers circuitry located on this board and isreduced to +5VDC. +5VDC is converted to -5VDC and +/-3VDC. The +5and -5VDC powerslogic circuitry on this board, while the +/- 3VDC provides the reference voltage for the positionsensors. Two green LEDs provide visual indication of the +24 and +5VDC status (ON indicatesthe respective voltage is present).

The 240VAC power is connected through control relays to the pedestal motors.


Figure 2-4 shows the interconnections between the Distribution board, the TZ Drive Board, thePedestal Motors, and the Pedestal Position Encoders. Table 2-5 describes the interconnectionsbetween the Distribution board and the TZ Drive Board. Table 2-6 describes the line voltage(240VAC, line to line) between the Operator's Console Power Module and the TZ Drive Board.Table 2-7 describes the interconnections between the TZ Drive Board and the two pedestalmotors and their respective position encoders. The tables also identify the interconnectionconnector and pin assignments.


2-9

ARD+, ARD-

ATD+, ATD-SYSRESET+,

EMERGENCY+,

MAN_UP*, MAN_UP_RET

MAN_DOWN*, MAN_DOWN_RET

+24V

120V(A)_UP_LEFT

120V(A)_DWN_LEFT

120V(B)_LEFT

GND_PED

+3.0VREF

(Position Signal)

-3.0VREF

120V(A)_UP_RIGHT

120V(A)_DWN_RIGHT

120V(B)_RIGHT

GND_PED

+3.0VREF

(Position Signal)

-3.0VREF

TZDRIVEBOARD

LEFTPEDESTAL

MOTOR

To/From Distribution Board

To/FromOperator’s ConsolePower Module

LEFTPEDESTALPOSITIONENCODER

RIGHTPEDESTAL

MOTOR

RIGHTPEDESTALPOSITIONENCODER

120V(A)_RIGHT

120V(B)_RIGHT

GND_PED

120V(A)_LEFT

120V(B)_LEFT

GND_PED

Figure 2-4. Distribution Board/TZ Drive Board Interconnection Diagram

Figure 2-4 shows the interconnections between the Distribution board, the TZ Drive Board, thePedestal Motors, and the Pedestal Position Encoders. Table 2-5 describes the interconnectionsbetween the Distribution board and the TZ Drive Board. Table 2-6 describes the line voltage(240VAC line to line) between the Operator's Console Power Module and the TZ Drive Board.Table 2-7 describes the interconnections between the TZ Drive Board and the two pedestalmotors and their respective position encoders. The tables also identify the interconnectionconnector and pin assignments.


2-10

Table 2-5. Distribution Board/TZ Drive Board Interconnection Descriptions

Signal Description Pin(s)

ARD+ARD-

Asynchronous Receive Data. JP1-11JP1-12

ATD+ATD-

Asynchronous Transmit Data. JP1-14JP1-15

SYSRST+SYSRST-

System Reset. Resets the TZ Drive board. JP1-17JP1-18

EMERGENCY+EMERGENCY-

Enables manual operation of the pedestals in the caseof an emergency (under control of the Control PanelTable switch on the Patient Table).

JP1-20JP1-21

MAN_UP*MAN_UP_RET

Raises the Patient Table in the case of an emergency. JP1-23JP1-24

MAN_DWN*MAN_DWN_RET

Lowers the Patient Table in the case of an emergency. JP1-26JP1-27

+24V DC power for the Motor Controller board. JP1-5, JP1-6

+6.5V Not used. JP1-2, JP1-3

Table 2-6. Operator's Console Power Module/TZ Drive BoardInterface Descriptions


120V(A)_LEFT AC voltage (120) to drive the Left Pedestal motor. JP6-4

120V(B)_LEFT AC voltage (120) to drive the Left Pedestal motor. JP6-5

120V(A)_RIGHT AC voltage (120) to drive the Right Pedestal motor. JP6-1

120V(B)_RIGHT AC voltage (120) to drive the Right Pedestal motor. JP6-2

GND_PED Ground line to the Left/Right Pedestal motor. JP6-3/JP6-6


2-11

Table 2-7. TZ Drive Board/Pedestal Motors and Position EncodersInterconnection Descriptions


120V(A)_UP_LEFT AC voltage to the Left Pedestal motor to move the leftend of the Patient Table up.

JP5-1

120V(A)_DWN_LEFT AC voltage to the Left Pedestal motor to move the leftend of the Patient Table down.

JP5-2

120V(B)_LEFT AC line to the Left Pedestal motor. JP5-3

GND_PED Ground line to the Left Pedestal motor. JP5-4

120V(A)_UP_RIGHT AC volt

model qdr 4500 qdr for windows - frank's hospital ......hologic hologic inc. 35 crosby drive...

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